Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Apr. 30, 2022	Jul. 31, 2021
Accounts receivable, allowance for credit loss, current	$ 5,061	$ 4,438
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000	10,000
Preferred stock, shares issued	0	0
Common Class A [Member]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	35,000	35,000
Common stock, shares issued	3,272	3,272
Common stock, shares outstanding	1,574	1,574
Treasury stock, shares	1,698	1,698
Common Class B [Member]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	200,000	200,000
Common stock, shares issued	27,725	26,379
Common stock, shares outstanding	24,667	24,187
Treasury stock, shares	3,058	2,192